The present invention relates to a vehicle seat, and more particularly, to having a seat part and a backrest, an upholstery which is integrated in at least one of the seat part and the backrest and which has a ventilation layer through which air can flow, the ventilation layer consisting of a large-meshed spaced knit, and which has an air-permeable upholstery cover spanning a surface facing a seat occupant, and devices for ventilating the ventilation layer.
Known ventilated vehicle seats are used for improving the sitting climate comfort when a parked vehicle is entered which is overheated as the result of extended sun radiation as well as for longer driving times.
In the known vehicle seat described in DE 39 03 303 A1, the devices for ventilating the ventilation layer, which is constructed as an indentation-proof support mat made of a large-meshed, irregular synthetic-thread knit, consists of three ray-shaped and curved tube connections made of an elastic material which are inserted into a central profile recess in the area of the rearward edge of the seat part and are connected by way of a central distributor to the blow-out opening of a vehicle-side fan. The supply of warm or cold air into the ventilation layer can be continuously regulated by a control flap. The bottom side of the upholstery which faces away from the breathing upholstery cover is provided with an air-impermeable covering. The fan delivers an air flow into the upholstery of the seat part and the backrest. The air flow flows through the ventilation layer and reaches the body surfaces of the sitting person through the pores of the upholstery cover.
The seat ventilation using air-conditioned air has the decisive disadvantage that, as the result of the adjustability of the vehicle seat for setting the seat position which is optimally adapted to the seat user, high-expenditure and extensive flexible air ducts are required for connecting the central distributor to the fan. In addition, air-conditioned air cooling is extremely sluggish so that no rapidly effective cooling of the body contact surfaces of the vehicle seat can be achieved in a vehicle seat which is overheated by parking in the sun. The blowing-in of precooled air in addition leads to the risk of a fast overcooling of individual body zones which is intensified in that the air flows in at the rearward area of the seat part or at the lower area of the backrest and causes the strongest cooling there.
DE 40 14 550 A1 describes a seat for achieving an effective removal of moisture which has penetrated into the upholstery cover as the result of the transpiration of the sitting person. A layer of the upholstery which is situated behind the upholstery cover and has a low air flow resistance in a central area of the backrest is connected with a suction blower. The suction blower is integrated into the backrest and carries away the suction air carrying the moisture through an opening in the backrest wall. The rearward side of the air-permeable upholstery layer facing away from the breathing upholstery cover is covered by a blocking layer which is made of an air-impermeable material and which, in addition, is used as a support for the spirals of an electric seat heater.
DE 16 54 400 B2 describes a seat composed of two plastic buckets. The surface of the bucket parts facing the body of the sitting person is perforated and the hollow space enclosed by the seat buckets is connected to a switchable fan supplying suction air or compressed air. As an alternative, the switchable fan is arranged within the hollow space between the bucket parts. Also, the compressed air can be heated to thus temper the seat buckets.
An object of the present invention is to improve a vehicle seat with a sitting climate comfort such that, on one hand, disturbing air connection hoses are avoided and, on the other hand, a rapidly effective cooling is ensured of seat surfaces heated considerably by sun radiation starting with the entering of the parked vehicle. A draft-free uniform cooling of the body contact zones of the sitting person when the seat is heated can be guaranteed by the present invention without the risk of damage to a person's health as well as the continuous carrying-away of the transpiration moisture generated by the sitting person.
This object has been achieved according to the present invention by providing that the ventilation layer covers an upholstery layer at least in the body contact area over the whole surface, in that the devices for ventilating the ventilation layer have a plurality of electrically driven miniature fans which are integrated in the upholstery layer and which are arranged in air ducts which penetrate the upholstery layer from the frontal side facing the ventilation layer to the rearward side facing away from the ventilation layer, and in that the air ducts are distributed in the upholstery layer in an arrangement which causes an area-wide ventilation of the ventilation layer which is as uniform as possible.
The vehicle seat according to the present invention has, among others, the advantage that, because of the arrangement of a plurality of miniature ventilators or fans directly in the upholstery, a large air throughput is achieved while the fan dimensions are small. This throughput will also cool upholstery heated by sun radiation within a short time down to a comfortable temperature. The ventilation air is taken out at the underside of the seat. That is, the take out of the ventilation air is in an area of the vehicle interior in which the lowest air temperature exists and generally remains below the average skin temperature of a human being at approximately 34.degree. C. which considerably raises the effectiveness of the cooling. As the result of this large air throughput with an advantageously tempered air, excellent cooling of the vehicle seat is achieved also without the use of a cooling unit and the overcooking phenomena with respect to the sitting person which may be harmful to the person's health in the case of the cooled air are avoided. With the elimination of a cooling unit and the integration of the ventilators and fans into the vehicle seat itself, all disturbing flexible tubes are avoided.
The miniature fans or miniature ventilators also have the advantage that they can be arranged in the seat part and the backrest at various densities adapted to a transpiration activity of different intensities of the body regions of the sitting person. In addition, they may be controlled such that they run at different rotational speeds and/or that the time sequence of the rotational speed is varied corresponding to the momentary requirements. If a remote door locking system exists, the switching-on of the miniature fans can be coupled with the remote control so that the ventilation of the vehicle seat starts even before the vehicle is entered.
Moreover, the miniature fans can be switched from a blowing mode to a sucking mode so that, after entering the vehicle and taking the seat, it is also possible to remove moisture from the skin and clothing of the sitting person with the suction air. As the result of the ventilation layer, an absolutely draft-free cooling which is uniform over the body zones is ensured in the body contact surfaces of the vehicle seat so that there is no danger of catching a cold.